Two new cases of whooping cough were reported at Stevenson High School on Tuesday, making for a total of 35 cases in Lincolnshire this year.
Whooping cough, or pertussis, causes severe, violent coughing and spreads easily in groups during the first two weeks after the cough starts. Other signs include cold-like symptoms like a runny nose but usually no fever.
Sudents at Stevenson High have come down with whooping cough since late September.
Lake County Health Department urges anyone with a mild, worsening cough to see their doctor. Stevenson High recently welcomed CDC researchers to do a whooping cough study with students.
The CDC is studying if whooping cough vaccines have lost their effectiveness because most Stevenson students with whooping cough had been vaccinated.